If you are... :
1) Happy with the way your stock suspension rides/handles
2) Don't plan to do much off roading
3) Don't have the Off Road Package / Rebel
4) Not concerned about suspension travel, particularly up travel
5) Running a wheel/tire setup not too much heavier than stock
... then a spacer will probably do fine.
If you want to improve the handling, control, or towing characteristics you might consider leveling via a strut or coilover. If you If you regularly do any off roading beyond a fire road then it's fairly imperative.
Note: pretty much no aftermarket strut/coilover will improve on the stock Ram ride *comfort*, but most options should improve on handling/control. People prioritize different characteristics, which is why some people can be disappointed in a ride that someone else loves. Happens with the Bilstiens a lot because you loose that Cadillac float, and instead "feel" more of the road - which some people love, some people can't stand.